MacroPackage: exclToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version

def-stream-class

Arguments: class-name superclasses slots &rest options

This macro is similar to defclass, except that various stream accounting is performed. If a slot is mentioned that is already known to the Allegro CL streams system, it is given a fixed-index value. Also, if an :initform or :logior option is specified, then an initialize-instance :before method is automatically created to ensure that the slot has the specified value before shared-initialize time.

The :logior option is an Allegro CL-specific variant of an initform. Specifying :logior 128 means apply logior to 128 and the previous value of the slot (which should be numeric and defaults to 0). This is a shorthand for specifying a value for the slot in a much more complicated way, and it requires the :before referenced above because it is not a standard CLOS feature.

You must load the :iodefs module to use this macro. Do that by evaluating (require :iodefs). (It is not an error to evaluate that form if the module is already loaded.) This macro is intended for implementing device-level functionality and should not be used except for that purpose. See Simple-stream Description in streams.htm for a description of the device-level.

See streams.htm for information on the simple-streams implementation in Allegro CL.


Copyright (c) 1998-2012, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 9.0. This page was not revised from the 8.2 page.
Created 2012.5.30.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version